nRF52840 TWI library error

RE: nRF52840 TWI library error

adragocelestica — Tue, 08 May 2018 09:24:48 GMT

In the end i found the way to make it work. I will explain in case someone else is in the same situation.

Basically, I declare the SPI instances and the TWI instance, as you suggested. Then, in my sdk_config.h, I add the following line:

#ifndef PERIPHERAL_RESOURCE_SHARING_ENABLED
#define PERIPHERAL_RESOURCE_SHARING_ENABLED 1 //https://devzone.nordicsemi.com/f/nordic-q-a/17035/twi0-and-spi0-time-multiplex
#endif

I initialize the SPIs as in the peripherals/spi example. Then, when I want to use them, I do it like this:

spi0_init();
spi0_xfer_done = false;
spi0_tx_buf[0]=0x01;
spi0_tx_buf[1]=0x8F;
APP_ERROR_CHECK(nrf_drv_spi_transfer(&spi0, spi0_tx_buf, spi0_length, spi0_rx_buf, spi0_length));
while (!spi0_xfer_done)
{
	__WFE();
}
nrf_drv_spi_uninit(&spi0);

This way, the code compiles and seems to do stuff. I am not getting the expected results, so something may be badly configured, but it is good as a starting point. Basically, I am initializing and uninitializing the peripheral every time I use it because I cannot use TWI0 and SPI0 at the same time since they share the base address.

The SPI transaction seems to be executed, but what I receive in spi0_rx_buf is a long number (always the same number), regardless of what I am writing. If I am getting something wrong, please do not hesitate to correct me.

Best regards,

Alin O. Dragomir

RE: nRF52840 TWI library error

Jørgen Holmefjord — Fri, 04 May 2018 14:16:51 GMT

There is no examples in the SDK implementing 3 SPI instances, but you can easily enable this yourself in the default SPI example:

In sdk_config.h, set SPI1_ENABLED and SPI2_ENABLED to 1, in main, add two new instances on SPI1 and SPI2, in addition to the existing instance of SPI0:

static const nrf_drv_spi_t spi0 = NRF_DRV_SPI_INSTANCE(0); /**< SPI instance 0. */
static const nrf_drv_spi_t spi1 = NRF_DRV_SPI_INSTANCE(1); /**< SPI instance 1. */
static const nrf_drv_spi_t spi2 = NRF_DRV_SPI_INSTANCE(2); /**< SPI instance 2. */

RE: nRF52840 TWI library error

adragocelestica — Fri, 04 May 2018 07:16:48 GMT

I am trying the same approach for SPI, that is, copying from the sdk_config.h file in the SPI example, but i still get the same compilation error.

../../../../../../integration/nrfx/legacy/nrf_drv_spi.h:120:37: error: 'NRF_DRV_SPI_INSTANCE_1' undeclared here (not in a function)

Is there an sdk_config.h file that implements 3 SPI interfaces? I am implementing one right now, and I am having trouble, I don't expect to be able to do it for 3 interfaces this way. Thank you.

RE: nRF52840 TWI library error

adragocelestica — Thu, 03 May 2018 10:47:05 GMT

the issue was in my sdk_config.h. What I did is profit from the fact that this file is written with "ifdefine", and I just copied and pasted one after the other the code from different sdk_config.h files from different examples. That way, I only modified what was missing, and now the TWI is working. I will try to do the same for SPI, hopefully it will work too.

RE: nRF52840 TWI library error

Jørgen Holmefjord — Wed, 02 May 2018 09:20:41 GMT

I'm not able to reproduce your exact issue, but it sounds like there is some wrong configuration in your sdk_config.h file. Please make sure you have set the NRFX_TWI/TWIM and TWI_ENABLED configs similar to the example:

RE: nRF52840 TWI library error

adragocelestica — Wed, 02 May 2018 08:30:44 GMT

I am having the exact same problem with SPI, and I suspect it has something to do with sdk_config.h. I have backed up my project and tinkered a little with it, trying to copy and paste the parts that are missing in my sdk_config.h and that are present in the one in the example, but I still get the same result. I tried to use the big generic sdk_config.h from \config\nrf52840\config , and I got different errors, so the solution to this one must have something to do with sdk_config.h yet I cannot figure out what it is.